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P0300, P0301, P0302, P0103

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Triparadox, Mar 12, 2019.

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  1. Triparadox

    Triparadox Active Member

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    I just purchased a car not very long ago (within one month) and it showed me an engine light indicator. Once plugged with OBD2, it appeared that there were multiple misfiring from Cyl. 1 and Cyl. 2. I swapped both spark plugs and ignition coil as follow:

    1 to 4
    2 to 3

    I resetted the indicator. Today it came back again, still with Cyl. 1 and Cyl. 2 with an additional P0103 (MAF). Can anyone give me some suggestion???
     
    #1 Triparadox, Mar 12, 2019
  2. The Critic

    The Critic Resident Critic

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    The misfires, at least at this point, may be due to the MAF issue. Address the MAF fault before addressing the misfires. If you have access to a scanner, check to make sure that you are seeing at least 1.8 g/sec at idle. There are probably better ways of testing a MAF but regardless, you need to address the MAF problem before the misfires.
     
    #2 The Critic, Mar 13, 2019
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  3. bisco

    bisco cookie crumbler

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    you're gonna get confused with two threads on the same problem
     
    #3 bisco, Mar 13, 2019
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  4. Triparadox

    Triparadox Active Member

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    Sure, I'll try to clean it when I have the time. I also tried to find the 2010 Prius cleaning MAF guidance.. No luck until now.. Mind helping me on that one?

    Yes. I was at phone the first time, so I didn't really see the troubleshoot section.
     
    #4 Triparadox, Mar 13, 2019
    Last edited by a moderator: Mar 14, 2019
  5. Triparadox

    Triparadox Active Member

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    BTW there's an information I forget to add:

    Sometimes, when I start the engine up, there will be rattling vibration and sound for the first couple seconds (longest one was around 9 seconds). It's not always. If after that I turn off and turn the engine on again, it won't rattle. After a long period of time, there's a high chance it will rattle, but again, not always... like 75% chance.
     
    #5 Triparadox, Mar 13, 2019
  6. The Critic

    The Critic Resident Critic

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    The MAF sensor is located on the backside of the air intake tube. IIRC it uses phillips screws. Remove and clean if you desire, but I have never had success with cleaning MAFs.

    How's your coolant level? In my experience if this engine suddenly develops a start-up rattle at high mileage, there is a high probability of headgasket failure.
     
    #6 The Critic, Mar 14, 2019
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  7. Triparadox

    Triparadox Active Member

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    I just refilled the coolant to the appropriate level last couple days.. I'll see tomorrow. What if it actually drops below the gauge? Is it head gasket failure? Is this easy to fix? Expensive?
     
    #7 Triparadox, Mar 15, 2019
  8. The Critic

    The Critic Resident Critic

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    Not sure which "gauge" you are referring to. The easiest way to check for headgasket failure on these engines is to pressurize the cooling system overnight (with a pressure tester), then remove the spark plugs. Then use an inspection camera to inspect the tops of the pistons for signs of coolant intrusion.
     
    #8 The Critic, Mar 15, 2019
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  9. Triparadox

    Triparadox Active Member

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    I do not have the pressure tester... I'm complete beginner with limited access to tools.
     
    #9 Triparadox, Mar 15, 2019
  10. Triparadox

    Triparadox Active Member

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    Update: I just checked the coolant reservoir level. It's below LOW now even though I'm pretty sure I filled it up to the appropriate level couple days ago.
     
    #10 Triparadox, Mar 15, 2019
  11. FnRedPrius

    FnRedPrius Active Member

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    Coolant loss isn't always consistent with a head gasket failure. Ours went thru almost a gallon it just over a week, but since the problem became apparent in early December total loss has been about 2 gallons. As @The Critic said, wet piston tops after a cold soak will probably be the best indication.
     
    #11 FnRedPrius, Mar 15, 2019
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